The is the B) doing background research about the question
I got 134.91 but if you round it you’ll get 135
Answer:
Explanation:
Half time is period required to desintegrating the half of the initial number of atoms. Then, the total time is:
<span>nuclear symbol consists of three parts: 1. the symbol of the
element; 2. the atomic number of the element;3. the mass of the element. for
the above problem, the symbol for potassium is k. it's atomic number is 40. the
number of protons is 19. so we denote this in the following nuclear symbol; 40
k 19</span>
Answer:
What is mole used for?
Explanation:
The mole is widely used in chemistry as a convenient way to express amounts of reactants and products of chemical reactions.
SI base units: Base unit (Dimensionless)
Symbol: mol
Unit of: Amount of substance
Unit system: SI base unit
